Systems and methods for multi-module control of a hydrogen powered hybrid electric powertrain

ABSTRACT

The present disclosure provides systems and methods for a hydrogen-powered hybrid electric powertrain and the associated hydro-electro-aero-thermal management system (HEATMS).

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application hereby claims the benefit of andpriority to U.S. Provisional Patent Application No. 63/068,853, titledSYSTEMS AND METHODS FOR MULTI-MODULE CONTROL OF A HYDROGEN POWEREDHYBRID ELECTRIC POWERTRAIN, filed Aug. 21, 2020, which is incorporatedherein in its entirety by reference thereto.

BACKGROUND

Vehicles may be operated using a fuel source. The fuel source may have aspecific energy corresponding to an amount of energy stored orextractable per unit mass of fuel. The fuel source may be provided tovarious vehicles to enable such vehicles to generate energy and deliverpower to a propulsion system for movement and transportation.

SUMMARY

Embodiments of the present technology provide systems and methods formulti-module control of a hydrogen-powered hybrid electric powertrainthat overcomes drawbacks of the prior art and provides additionalbenefits. One aspect of the present technology provides a method foroptimizing operation of an aerial vehicle having a hydrogen-poweredhybrid electric powertrain. The method comprises providing hydrogen fuelto one or more fuel cell stacks, directing a first amount of air to theone or more fuel cell stacks powered by the hydrogen fuel and generatinga first output of electrical power for use at least by an electric motorof the hydrogen-powered hybrid electric powertrain, and operating theelectric motor using the generated electrical power, wherein thegenerated electrical power is provided to the electric motor withoutpassing through or being stored in a battery.

The method also includes predicting one or more changes in an electricalpower demand of the powertrain during operation of the electric motor,and controlling an amount of air flow to the one or more fuel cellstacks to direct a second amount of air to the one or more fuel cellstacks based at least in part on the one or more predicted changes inthe electrical power demand of the powertrain, wherein the first amountof air is different than the second amount of air provided to the one ormore fuel cell stacks. The second amount of air is provided to the oneor more fuel cell stacks before occurrence of the predicted electricalpower demand for generation of a second output of electrical power bythe one or more fuel cell stacks at or before occurrence of thepredicted electrical power demand of the powertrain, wherein the secondoutput of electrical power is different than the first output ofelectrical power, thereby reducing a transient period for delivery ofthe electrical power to the electric motor of the powertrain.

The amount of air flow can be controlled in part by controllingmechanical power to one or more compressors that direct airflow towardthe one or more fuel cell stacks. The compressors are powered at leastpartially by a peripheral electrical power unit. The second amount ofair is provided to the fuel cell stacks at a time so the fuel cellsprovide sufficient electrical power to meet the predicted electricalpower demand before the occurrence of the predicted demand of theelectrical power output. The fuel cell stacks and the electric motor canbe coupled to radiators for dissipating heat generated at least by thefuel cell stacks and the electric motor, and wherein the fuel cellstacks generate exhaust water when generating the generating electricalpower. The exhaust water can be applied to the radiators for evaporativecooling for dissipation of the heat generated at least by the fuel cellstacks and the electric motor.

The method can include using at least one of (1) one or more sensorsonboard the aerial vehicle and (2) data and automated observations fromone or more other aircrafts, detecting a first set of atmosphericconditions in an aircraft-operating environment that indicates contrailformation from the aerial vehicle would occur upon release in theenvironment of exhaust water generated by one or more fuel cell stacks.The exhaust water onboard the aerial vehicle is temporarily stored toblock the contrail formation as the aerial vehicle is navigating throughthe environment during first set of atmospheric conditions. A second setof atmospheric conditions can be detected in the environment in which itis unlikely to cause contrail formation from the aerial vehicle, thestored exhaust water is released from the aerial vehicle into theenvironment as the aerial vehicle is navigating through the environmentwithout forming a contrail.

An embodiment of the present technology provides a thermally managedhydrogen-powered hybrid electric powertrain system for a hydrogenpowered vehicle. The system comprises one or more fuel cell stackscomprising a plurality of hydrogen fuel cells configured to processhydrogen fuel to generate electricity, first thermal energy, and exhaustwater. One or more primary electric power units receive the electricitygenerated by the one or more fuel cell stacks, wherein the electricityis provided from the one or more fuel cell stacks to the one or moreprimary electric power units without passing through or being stored ina battery, and wherein the one or more primary electric power unitsgenerates second thermal energy. One or more radiators are configured toreceive and thermally dissipate the first and second heat, and one ormore pumps are configured to transmit coolant to the one or moreradiators. One or more fuel cell stacks are configured to transmitthermal energy to the one or more radiators, and a primary electricpower unit is configured to transmit the thermal energy to the one ormore radiators and receive electrical power from the one or more fuelcell stacks. A turbine receives first mechanical power from the one ormore fuel cell stacks, a second compressor receives the mechanical powerfrom the turbine and to direct first compressed air to the turbine andthe one or more fuel cell stacks, a first compressor provides secondcompressed air to the second compressor, and a water distribution systemreceives the exhaust water generated by the one or more fuel cell stacksand to direct the exhaust water an exhaust outlet.

The system can further comprise a speed reducer coupled to the primaryelectric power unit and configured to transmit thermal energy to thepumps and receive mechanical power from the primary electric power unit,and a peripheral electric power unit that transmits the thermal energyto the one or more pumps, wherein the first compressor receives powerfrom the peripheral electric power unit. The system can include aperipheral electric power unit that provides electrical power to thefirst compressor, and a battery that receives the electrical powergenerated from the fuel cell stacks and transmit the electrical power tothe peripheral electric power unit, where in the battery does notprovide electrical power to the primary electrical power unit. At leasta portion of the exhaust water generated by the fuel cell stacks canpass through the turbine, and the turbine is configured to direct theexhaust water to the water distribution system. The water distributionsystem can have a spray bar forming the exhaust outlet and configured todirect the exhaust water onto the radiator.

The system in at least one embodiment comprises a hydrogen-poweredpowertrain and hydro-electro-aero-thermal management system (HEATMS)configured to control and manage thermal energy generated by thehydrogen-powered powertrain. The HEATMS is configured to predict one ormore changes in an electrical power demand of the hydrogen-poweredpowertrain during operation of the primary electrical power unit. TheHEATMS controls an amount of air mass flow rate to the one or more fuelcell stacks to direct an amount of air to the one or more fuel cellstacks based at least in part on the one or more predicted changes inthe electrical power demand of the powertrain. The amount of air isprovided to the one or more fuel cell stacks before occurrence of thepredicted electrical power demand for generation of an output ofelectrical power by the one or more fuel cell stacks at or beforeoccurrence of the predicted electrical power demand of the powertrain,wherein the output of electrical power is timed to reduce a transientperiod for delivery of the electrical power to the primary electricalpower unit.

One aspect of the technology described herein is a method for optimizingoperation of an aerial vehicle having a hydrogen-powered hybrid electricpowertrain, the method comprising: predicting one or more changes ordemands in an electrical power output of one or more hydrogen fuel cellstacks located on the aerial vehicle; and controlling an optimal amountof air mass flow rate at an inlet to the one or more fuel cell stacksbased at least in part on the one or more predicted changes or demandsto the electrical power output, thereby reducing a transient period orlag time for delivery of the electrical power output by the powertrain.

In some embodiments, the optimal amount of air mass flow rate to thefuel cell stacks is controlled in part by controlling mechanical powerto one or more air compressors. In some embodiments, the one or morecompressors are powered by a battery and a peripheral electrical powerunit. In some embodiments, the optimal amount of air mass flow rate iscontrolled prior to an occurrence of the one or more changes or demandsin the electrical power output. In some embodiments, the one or morechanges or demands in the electrical power output are predicted based atleast in part on one or more of the following: one or more inputs from apilot of the aerial vehicle; a current, previous, or next position ofthe aerial vehicle; a flight path comprising a plurality of spatialcoordinates; or atmospheric weather conditions.

Another aspect provided herein is a method for preventing or controllingcontrail formation from an aerial vehicle, the method comprising: usingat least one of (1) one or more sensors onboard the aerial vehicle and(2) data and automated observations from one or more other aircrafts, todetect a first set of atmospheric conditions in a first environment thatcauses or is likely to cause contrail formation from the aerial vehicle;and collecting and storing water generated by one or more fuel cellstacks onboard the aerial vehicle to reduce or eliminate release of thewater while the atmospheric conditions exist to avoid contrail formationas the aerial vehicle is navigating through the first environment.

In some embodiments, the method further comprises using at least one of(1) the one or more sensors onboard the aerial vehicle and (2) the dataand automated observations from the one or more other aircrafts todetect a second set of atmospheric conditions in a second environmentthat does not or is unlikely to cause contrail formation from the aerialvehicle, and releasing the stored water from the aerial vehicle into thesecond environment as the aerial vehicle is navigating through thesecond environment.

Another aspect provided herein is a method of de-icing an aerialvehicle, the method comprising: circulating heat generated by one ormore fuel cell stacks to one or more parts of the aerial vehicle, andusing the circulated heat to prevent ice formation at the one or moreparts of the aerial vehicle. The one or more parts can comprise a wingor body of the aerial vehicle. The circulated heat can be used toprevent ice formation on the one or more parts of the aerial vehiclewhen the aerial vehicle is on the ground. The circulated heat can beused to prevent ice formation on the one or more parts of the aerialvehicle when the aerial vehicle is in flight.

Another aspect provided herein is a powertrain and thermal managementsystem for a hydrogen-powered vehicle. The system comprises ahydrogen-powered hybrid electric powertrain and an associatedhydro-electro-aero-thermal management system (HEATMS). The system caninclude one or more radiators; one or more pumps configured to transmitcooling fluid to the one or more radiators; one or more fuel cell stacksconfigured to transmit thermal energy to the one or more radiators; aprimary electric power unit configured to transmit the thermal energy tothe one or more radiators and receive electrical power from the one ormore fuel cell stacks; a speed reducer configured to receive mechanicalpower from the primary electric power unit and transmit the thermalenergy to the one or more pumps; a peripheral electric power unitconfigured to transmit power to a first compressor and the thermalenergy to the one or more pumps; a turbine configured to receive themechanical power (e.g., fluid power) from the one or more fuel cellstacks; a second compressor configured to receive the mechanical powerfrom the turbine, and to receive the fluid from the first compressor;and a propeller configured to receive the mechanical power from thespeed reducer.

In some embodiments, the first compressor is configured to receive afluid from an inlet. The peripheral electric power unit can beconfigured to provide the mechanical power to a peripheral aircraftcomponent. The system has a battery configured to receive the electricalpower from the one or more fuel cell stacks and transmit the electricalpower to the peripheral electric power unit. In some embodiments, thesystem has a water distribution system that receives water generatedfrom the fuel cell stack and distributes the water onto or into theradiator or other heat exchanger to facilitate heat removal. The systemcan comprise a valve system and a fluid storage unit configured toreceive and temporarily store a fluid that is output from the turbineand the fuel cell stack. In some embodiments, the fluid storage isconfigured to selectively transmit the fluid to an exhaust or fordistribution to the radiator. In some embodiments, the system furthercomprises a deicing system configured to receive a fluid from theturbine. In some embodiments, the deicing system is configured toselectively transmit the fluid to an exhaust. In some embodiments, theturbine is configured to further transmit a fluid to an exhaust. In someembodiments, the speed reducer comprises a gearbox, a timing belt, anelectromagnetic propeller clutch, or any combination thereof.

In some embodiments, the primary electric power unit has a peak power ofgreater than about 1,600 kW, and in some embodiments an operating rangeof approximately 1,600 kW-1,955 kW. In some embodiments, the peripheralpower unit has a peak power of greater than about 400 kW, and in someembodiments an operating range of approximately 400 kW-489 kW. In someembodiments, the one or more fuel cell stacks have a specific power ofgreater than about 3 kW/kg, and in some embodiments an operating rangeof approximately 3 kW/kg-3.67 kW/kg. In some embodiments, the system isconfigured to reject at least about 2,000 kW from the one or more fuelcell stacks. In some embodiments, the system is configured to reject atleast about 300 kW from the primary electric power unit or theperipheral electric power unit. In some embodiments, the fluid is water,air, or any combination thereof. In some embodiments, the cooling fluidis water, a coolant, an oil, or any combination thereof.

Another aspect provided herein is a non-transitory computer-readablestorage media encoded with a computer program including instructionsexecutable by a processor to create a hydro-electro-aero-thermalmanagement system (HEATMS) application comprising: a first moduleconfigured to receive sensor data; a second module configured todetermine, based on the sensor data: a peripheral electric power output;a primary electric power output; a battery power output; a pump power, apump fluid flowrate, or both.

In some embodiments, the sensed data comprises an ambient airtemperature, ambient air pressure, aircraft velocity, aircraft altitude,aircraft global positioning system (GPS) or other global navigationsatellite system (GNSS) position, peripheral electric power unit outputvoltage, peripheral electric power unit output current, air inlet flowrate, air inlet temperature, air inlet pressure, air/water outlet flowrate, air/water outlet temperature, air/water outlet pressure, hydrogeninlet flow rate, hydrogen inlet temperature, hydrogen inlet pressure,speed reducer temperature, compressor inlet flow rate, compressor inlettemperature, compressor inlet pressure, compressor outlet flow rate,compressor outlet temperature, compressor outlet pressure, turbine inletflow rate, turbine inlet temperature, turbine inlet pressure, turbineoutlet flow rate, turbine outlet temperature, turbine outlet pressure,propeller rotational speed, radiator cooling fluid inlet temperature,radiator cooling fluid outlet temperature, a pilot control, or anycombination thereof. In some embodiments, the second module isconfigured to determine the peripheral electric power output, theprimary electric power output, the battery power output, the pump power,the pump fluid flow rate, or any combination thereof from the sensordata using a machine learning algorithm. In some embodiments, themachine learning algorithm is configured to determine a predicted flightevent based on the sensed data, and wherein the second module isconfigured to determine the peripheral electric power output, theprimary electric power output, the battery power output, the pump power,the pump fluid flowrate, or any combination thereof based on thepredicted flight event. In some embodiments, the predicted flight eventis a takeoff event, a cruise event, a climb event, a descent event, alanding event, or any combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the technology are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present technology will be obtained by reference tothe following detailed description that sets forth illustrativeembodiments, in which the principles of the technology are utilized, andthe accompanying drawings (also “Figure” and “FIG.” herein).

FIG. 1 schematically illustrates an aircraft with a hydrogen-poweredhybrid electric powertrain in accordance with some embodiments of thepresent technology.

FIG. 2 shows a first schematic of an exemplary hydrogen-powered hybridelectric powertrain and its associated hydro-electro-aero-thermalmanagement system (HEATMS), in accordance with some embodiments.

FIG. 3 shows an image of an exemplary fuel cell outlet turbine, inaccordance with some embodiments.

FIG. 4A is a schematic diagram of a fuel cell powertrain architecture inaccordance with an embodiment of the present technology.

FIG. 4B is a voltage-power per stack graph of the fuel cell powertrainarchitecture of FIG. 4A.

FIG. 4C is a voltage-time graph and sequence table of a startup sequenceof at least one embodiment of the present technology.

FIG. 4D is a schematic circuit diagram of a fuel cell powertrainarchitecture in accordance with at least one embodiment of the presenttechnology.

FIG. 4E is a schematic circuit diagram of a fuel cell powertrainarchitecture in accordance with another embodiment of the presenttechnology.

FIG. 5 shows an image of a first exemplary electric power unit androtational speed reducer, in accordance with some embodiments.

FIG. 6 shows an image of a second exemplary electric power unit androtational speed reducer, in accordance with some embodiments.

FIG. 7 shows an image of a third exemplary electric power unit androtational speed reducer, in accordance with some embodiments.

FIG. 8 shows an image of an aircraft comprising the exemplaryhydrogen-powered hybrid electric powertrain and its associatedhydro-electro-aero-thermal management system (HEATMS), in accordancewith some embodiments.

FIG. 9 is a schematic flowchart of a HEATMS application in accordancewith some embodiments.

FIG. 10 is a schematic flowchart of a predictive module of the HEATMSapplication with machine learning in accordance with some embodiments.

FIG. 11 shows a diagram of predicted flight events.

FIG. 12 schematically illustrates a computer system programmed orotherwise configured to implement methods provided herein.

DETAILED DESCRIPTION

While various embodiments of the technology have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions may occur to those skilled in theart without departing from the invention in accordance with thetechnology. It should be understood that various alternatives to theembodiments of the technology described herein may be employed.

Method for Optimizing Operation of an Aerial Vehicle Having aHydrogen-Powered Hybrid Electric Powertrain

One aspect provided herein is a method for optimizing operation of anaerial vehicle having a hydrogen-powered hybrid electric powertrain. Themethod comprises predicting one or more changes or demands in anelectrical power output of one or more fuel cell stacks located on theaerial vehicle; and controlling an optimal amount of air mass flow rateat an inlet to the one or more fuel cell stacks based at least in parton the one or more predicted changes or demands to the electrical poweroutput, thereby reducing a transient period or lag time for delivery ofthe electrical power output by the powertrain.

Hydrogen-Powered Hybrid Electric Powertrain

Aspects of the present technology provide a hydrogen-powered powertrainand thermal management system for an aerial vehicle or other vehicle.The system employs an interior fuel source, such as hydrogen fuel, togenerate energy and propulsive power, and to enable operation ofsupporting or peripheral systems within the aerial vehicles. Thehydrogen-powered powertrain system includes a powertrain that convertsthe hydrogen fuel to electricity. Such energy conversion componentscomprise fuel cell stacks comprising a plurality of hydrogen fuel cells,which convert the hydrogen fuel to electricity. A primary electricalpropulsion unit, such as a brushless permanent magnet motor, convertselectricity from the primary electrical propulsion unit to mechanicalpower. The primary electrical propulsion unit is connected to amechanical speed reducer and a propeller. The system also has a firstcompressor to condition ambient air, a peripheral electric power unit toprovide power for the first compressor, a second compressor to furthercondition ambient air, a turbine to provide power to the secondcompressor, pumps which transmit cooling fluid to one or more radiators,one or more radiators which remove heat from the system, and batterieswhich store electrical energy to power the peripheral electric powerunit or other electrical components of the aerial vehicle. Thebatteries, however, do not power the electric motor or other primaryelectrical propulsion unit. To provide stable and safe operation of sucha powertrain, the condition, input, and output of each component isregulated to ensure efficient and safe energy transfer and storage, andheat and/or fluid distribution and rejection. As such, provided hereinis a hydro-electro-aero-thermal management system (HEATMS) coupled tothe powertrain and configured to control the powertrain at least in partby adjusting and optimizing the operational parameters of each componenttherein to enable safe and continuous operation.

FIG. 1 is a schematic illustration of an aircraft 10 with one or morethermally managed powertrain systems 1000 comprising a hydrogen-poweredhybrid electric powertrain 1002 and an associatedhydro-electro-aero-thermal management system (HEATMS) 1004 in accordancewith embodiments of the present technology. In the illustratedembodiment the aircraft 10 has two thermally managed powertrain systems1000, although other aircraft or other vehicles can include one or morethan two thermally managed powertrain systems in accordance with thepresent technology. As seen in FIG. 2, the powertrain system 1000 of theillustrated embodiment comprises one or more radiators 2102, pumps 2101,a water distribution system 2120, fuel cell stacks 2103, a primaryelectric power unit 2114, a speed reducer 2115, a battery 2109, aperipheral electric power unit 2110, peripheral aircraft components2111, a turbine 2104, a second compressor 2108, a first compressor 2112,a propeller 2116, a fluid inlet 2113, a deicing system (2105), and afluid exhaust 2107.

The illustrated powertrain 1002 can comprise the fuel cell stacks 2103,the primary electric power unit 2114 (e.g. an electric, brushlessmotor), the speed reducer 2115, the propeller 2116, the peripheralelectric power unit 2110, and the battery 2109. The HEATMS 1004 workswith the powertrain 1002 to help with heat management and control duringoperation of the powertrain 1002 and other components of the aircraft 10(FIG. 1). The HEATMS 1004 can comprise the one or more radiators 2102,pumps 2101, the water distribution system 2120, the first compressor2112, the second compressor 2108, the turbine 2104, and the fluidexhaust 2107. It is to be understood that the thermally managedpowertrain system 1000 of other embodiments can include othercomponents, and some of the components of the powertrain 1002 may beused in connection with the thermal management of the system. Also, thecomponents of the HEATMS 1004 may be used in or with the powertrain 1002for power generation for the aircraft 10 (FIG. 1 or other vehicle). TheHEATMS 1004 is coupled to one or more controllers that communicate withand/or at least partially control components of the HEATMS 1004, thepowertrain 1002, or both.

In some embodiments, the pumps 2101 transmit cooling fluid through orpast other heat-generating components of the system and to the one ormore radiators 2102. Accordingly, the cooling fluid acts to carry heataway from the components in the system 1000 to the radiators 2102 forefficient thermal dissipation of the heat. For example, the fuel cellstacks 2103 transmit thermal energy to the one or more radiators 2102.In one embodiment, the fuel cell stacks 2103 are connected to a closedcooling loop containing a water-ethylene glycol coolant or other coolantthat flows to and/or through the radiator. The primary electric powerunit 2114 transmits thermal energy to the one or more radiators 2102. Inone embodiment, the primary electric power unit 2114 is connected toanother closed cooling loop containing oil or other coolant that flowsto and/or through the radiator. In some embodiments the fuel cell stack2103 and the primary electrical power unit 2114 can be connected toseparate cooling circuits or can be connected to the same coolingcircuit.

As seen in FIG. 2, the primary electric power unit 2114 receiveselectrical power from the fuel cell stacks 2103. The speed reducer 2115transmits thermal energy to the one or more radiators 2102. The speedreducer 2115 receives mechanical power from the primary electric powerunit 2114. The speed reducer 2115 comprises a gearbox, a timing belt, anelectromagnetic propeller clutch, or any combination thereof. A quantityof mechanical power transmitted from the primary electric power unit2114 to the speed reducer 2115 is determined by the HEATMS 1004.

The peripheral electric power unit 2110 transmits thermal energy to theone or more radiators 2102. The battery 2109 receives electrical powerfrom the fuel cell stack 2103 and transmits the electrical power to theperipheral electric power unit 2110. The battery 2109 can enable fasterresponse of electrical components of the system 1000 based on theconditions of the aircraft and/or pilot control. The battery 2109 doesnot provide power to the primary electric power unit 2114, so thebattery 2109 can be relatively small, lightweight, and configured toprovide sufficient power to the peripheral electrical power unit 2110 inoperation. A quantity of electrical power transmitted from the battery2109 to the peripheral electric power unit 2110 is determined by theHEATMS 1004. In some embodiments the battery 2019 is a rechargeable,lithium-based battery that can generate in the range of approximately10-30 kWh and weighs approximately 50 kg.

The turbine 2104 receives fluid, such as heated air and exhaust water,from the fuel cell stack 2103. In some embodiments, the secondcompressor 2108 is a turbine-driven compressor that receives mechanicalpower from the turbine 2104. The first compressor 2112 transmits afluid, such as air, to the second compressor 2108. The first compressor2112 of the illustrated embodiment is a motor driven compressor thatreceives mechanical power from the peripheral electric power unit 2110.A quantity of mechanical power transmitted from the peripheral electricpower unit 2110 to the first compressor 2112 is determined by the HEATMS1004. The propeller 2116 receives mechanical power from the speedreducer 2115. A quantity of thermal energy received by the one or moreradiators 2102 is determined and managed by the HEATMS 1004. A flow rateof thermal energy received by the one or more radiators 2102 is alsodetermined and managed by the HEATMS 1004.

In some embodiments, the first compressor 2112 receives air or otherfluid from an inlet 2113. In some embodiments, the peripheral electricpower unit 2110 provides mechanical power to one or more peripheralaircraft components 2111. The system 1000 further comprises an exhaustfluid subsystem 2106 receiving a fluid, such as the heated exhaust waterflowing from the fuel cell stack 2103 and through the turbine 2104. Thefluid subsystem 2106 can be coupled to the HEATMS 1004 and can be usedto selectively transmit the exhaust water or other fluid to the radiator2102 and/or to an exhaust 2107. The system 1000 further comprises adeicing system 2105 receiving a fluid, such as heated air and/or water,from the turbine 2104. The deicing system 2105 can selectively transmitthe fluid to the exhaust 2107. The HEATMS 1004 is configured to controland determine the quantity of fluid received, transmitted, or both bythe fluid subsystem 2106, the quantity and timing of fluid received,transmitted, or both by the deicing system 2105, and the quantity offluid released by the exhaust 2107. In some embodiments, the turbine2104 further transmits a fluid to an exhaust 2107 of the fluid subsystem2106. In the illustrated embodiment, the fluid is heated water and/orair. In other embodiments, the fluid can be water, air, a coolant, anoil, or any combination thereof.

In some embodiments, the primary electric power unit 2114 can be anelectric motor of the type described in U.S. patent application Ser. No.17/318,993, titled Systems and Methods for Storing, Transporting, andUsing Hydrogen, filed May 12, 2021, which is incorporated herein in itsentirety by reference thereto. The primary electric power unit 2114 hasa peak power of greater than about 800 kW, 900 kW, 1,000 kW, 1,100 kW,1,200 kW, 1,300 kW, 1,400 kW, 1,500 kW, 1,600 kW, 1,700 kW 1,800 kW,1,900 kW, 2,000 kW, 2,500 kW, or 3,000 kW. In some embodiments theprimary electric power unit 2114 is a brushless, permanent magnet motorthat has a power range of approximately 500 kW-1,600 kW. In someembodiments, the peripheral power unit 2110 has a peak power of greaterthan about 100 kW, 150 kW, 200 kW, 250 kW, 300 kW, 350 kW, 400 kW, 500kW, 600 kW, 700 kW, or 800 kW. In some embodiments, the fuel cell stack2103 has a specific power of greater than about 1 kW/kg, 1.5 kW/kg, 2kW/kg, 2.5 kW/kg, 3 kW/kg, 3.5 kW/kg, 4 kW/kg, 4.5 kW/kg, 5 kW/kg, 5.5kW/kg, or 6 kW/kg. In some embodiments, the system 1000 rejects at leastabout 1,000 kW, 1,250 kW, 1,500 kW, 1,750 kW, 2,000 kW, 2,500 kW, 3,000kW, or 4,000 kW thermal power from the fuel cell. In some embodiments,the system 1000 rejects at least about 100 kW, 150 kW, 200 kW, 250 kW,300 kW, 350 kW, 400 kW, 450 kW, 500 kW, 550 kW, or 600 kW thermal powerfrom the electric power unit. In the illustrated embodiment, theaircraft 10 is a hydrogen-powered, dual motor regional aircraft with apower train 1002 that provides at least 2 MW of gross power output(i.e., 1 MW gross power output per electric motor).

In some embodiments, the turbine 2104 receives power from the fuel cellstack 2103. The first compressor 2112 receives power from the peripheralpower unit 2110. The peripheral power unit 2110 receives power from thefuel cell stack 2103 and transmits power to peripheral aircraftcomponents 2111 and the first compressor 2112. The fuel cell stack 2103,the primary electric power unit 2114, the rotational speed reducer 2115,and the peripheral power unit 2110 are in fluidic communication with theone or more radiators 2102. The fluidic communication can comprise atransfer of water, coolant, oil, or any combination thereof. In someembodiments, the power transmitted by the peripheral power unit 2110,the rotational speed reducer 2115, the turbine 2104, the firstcompressor 2112, the second compressor 2108, or any combination thereof,at least in part is in the form of thermal power, mechanical power,and/or electrical power. The power received by the peripheral power unit2110 can provide power to a peripheral aircraft component 2111. Thepower can be transferred within the thermally managed powertrain system1000 through fluid conduits, rotational shaft couplings, linearcouplings, or any combination thereof.

Referring again to FIG. 2, operation of the system 1000 of an aircraftin at least one embodiment includes providing hydrogen fuel in eithergaseous or liquid phase to multiple hydrogen fuel cells in the fuel cellstack 2103. In the illustrated embodiment, each primary electric powerunit 2114 (e.g., the electric, brushless motor) is operatively coupledto multiple fuel cell stacks 2103 so as to receive adequate electricalpower for operation of the motor and other aircraft systems. Each fuelcell stack 2103 processes the hydrogen fuel and generates electricalpower that is provided to the motor or other primary electric power unit2114.

Upon processing the hydrogen fuel, the reaction in the fuel cell stack2103 generates exhaust water as well as heat. For example, in at leastone embodiment, the fuel cell stacks 2103 generate approximately 9 kg ofpure exhaust water for every 1 kg of hydrogen processed in the fuelcells. The exhaust water is typically atomized and at elevatedtemperatures, such as in the range of 65° C. and 85° C., which isgenerally close to the water's boiling temperature at approximately theaircraft's cruise altitude. The exhaust water can be directed throughthe turbine 2104 and then through fluid lines of the fluid subsystem2106 to the water distribution system 2120, which includes one or morespray bars 2121 that can have atomizing nozzles in front of or otherwiseadjacent to the radiator 2102. The exhaust water is sprayed through theatomizing nozzles onto the surface of the radiator 2102 where theexhaust water evaporates, so as to provide evaporative cooling at theradiator 2102. In addition to the evaporative cooling using the heatedexhaust water, the radiator 2102 also receives a flow of coolant, suchas water-ethylene glycol, oil, or other coolant, flowing in a closedcoolant circuit system. As indicated above, a plurality of closedcoolant circuits are used to carry heat generated in the powertrainsystem 1000 to the one or more radiators 2102 for thermal dissipation.

In some embodiments, over about 2.5 hours of use, the fuel cell stack2103 outputs approximately 1,800 kg of a pressurized and supersaturatedair and exhaust water mixture, which provides about 160 kWh of energy tothe second compressor 2108. The fluid subsystem 2106 that receives theheated exhaust water from the fuel cell stack 2103 and turbine 2014includes valving coupled to the HEATMS 1004 to control the fluid flow inthe water lines. Accordingly, when conditions are such that the exhaustwater should not be sprayed onto the radiator 2102, the exhaust watercan be directed to a fluid storage tank 2050 of the fluid subsystem 2106for temporary storage of the water. In some embodiments, a portion ofthe heat energy generated by the fuel cell stack 2103 is shed via thecoolant (e.g., water-ethylene glycol or the like) that is circulatedthrough a radiator 2102.

In some embodiments, the fuel cell stacks 2103 generate about 1,780 kWof heat energy and the electric power unit 2114 generates about 250 kWof heat energy. The combined heat energy shed via about 2000 L of thecoolant that is circulated by 15 kW pumps 2101 through the radiator2102. In some embodiments, the system 1000 further comprises a hydrogenpiping, a water piping of the fluid subsystem 2106, a water weep hole,the water storage tank 2050, a humidifier, a radiator, or anycombination thereof. In some embodiments, the hydrogen piping, the waterpiping, the water weep hole, the water storage, the humidifier, theradiator, or any combination thereof transmit heat, coolant, water, orany combination thereof to the pump. In some embodiments, per FIG. 2,the hydrogen piping, the water piping, the water weep hole, the waterstorage, the humidifier, the radiator, the purification system, or anycombination thereof receive heat, coolant, water, or any combinationthereof from the pump 2101. In some embodiments, the peripheral aircraftcomponents 2111 receive electrical power from the peripheral electricpower unit 2110. The peripheral aircraft components 2111 can comprise,as an example, a de-icing system, a hydraulic pump, an avionics system,a galley, an air conditioning system, or any combination thereof.

Referring now to FIG. 3, when the first compressor 2112 is operating,such as during startup or while the aircraft is moving, the firstcompressor receives airflow through the air inlet 2113 and compressesthe air. The first compressor 2112 provides the flow of compressed airto the second compressor 2108, which receives power from the turbine2104 and/or the fuel cell stack 2103. In some embodiments, the firstcompressor 2112, the second compressor 2108, or both comprise aturbocharger. The first compressor 2112, the second compressor 2108, orboth comprise an electric compressor, a mechanical compressor, or both.The first compressor 2112, the second compressor 2108, or both have amass flow at an altitude of about 10,000 feet in the range of about1,500 g/s to about 5,000 g/s.

The first and second compressors 2112 and 2108 drive airflow to the fuelcell stacks 2103 for processing with the fuel to generate theelectricity. Further, the first and second compressors 2112 and 2108 areactively controlled and are configured to effectively preload and driveor temporarily overdrive the associated fuel cell stack 2103 by drivinghigher air mass flow rates to the fuel cell stack 2103 at selectedtimes, thereby ensuring very fast transients or responses in real timeto power needs for immediate conditions or configurations. In someembodiments, the hydrogen fuel system providing the hydrogen to the fuelcell stack 2103 can include a recirculating flow of pressurized hydrogenfor instant availability of the hydrogen, such as when the first andsecond compressors 2112 and 2108 drive excess air to the fuel cell stackfor additional power output capacity.

The second compressor 2108 of the illustrated embodiment is coupled to asupplemental storage container, such as one or more pressurized tanks2214, that retain a selected volume of compressed air or other workingfluid. In some embodiments, the pressurized tank 2214 is configured tohold approximately 4 kg of air at a pressure of about 2 bar at sealevel. Other embodiments can use larger or smaller tanks with differentvolumes and/or pressures. The pressurized tank 2214 is coupled to thefuel cells stack 2103 and is configured to provide an on-demand flow ofair to the fuel cell stack 2103. For example, upon startup of theelectric motors 2114 and the fuel cell stacks 2103, the compressed airfrom the tank 2214 is provided to the fuel cells in the fuel cell stack2103 for instant airflow access while the first and second aircompressors 2112 and 2108 are being activated. The compressed air fromthe tank 2214 can also be provided to the fuel cell stack 2103 duringother conditions for which instant air access may be needed or desired.

As indicated above, the fuel cell stack 2103 is configured to provideelectricity to the system's small battery 2109, which is coupled to theperipheral electrical power units 2110, but not to the electric motor2114. Accordingly, the small battery 2109 provides a temporary powersource to the aircraft's peripheral components for a short time toprovide the required initial levels of electrical power while the fuelcell stack 2103 is being activated. For example, during motor and systemstartup, the small battery 2019 can be used to initially power selectedaircraft components or systems, and the compressed air from the one ormore pressurized tanks 2214 can be used for instant access to air flowto the fuel cell stack 2103. When the fuel cell stack 2103 is operating,it also provides electricity to the peripheral electrical power unit2110, which is coupled to and powers the first compressor 2112. Once thefuel cell stack 2103 and the first and second compressors 2112 and 2108are activated and operating, the one or more tanks 2214 can be refilledand/or repressurized, and the small battery 2109 can be recharged forsubsequent use. In some embodiments, the peripheral electrical powerunit 2110 can be integrated with the first compressor 2112.

In some embodiments, each fuel cell stack 2103 is provided with athermal trigger or fuse 2130 to shut down the associated fuel cell stackupon reaching a thermal threshold. This configuration can avoidoverheating and thermal runaway of the hydrogen-powered fuel cell stack2103. In the illustrated embodiment, the thermal fuse 2130 can be apassive, fail-safe thermal fuse, such that the flow of hydrogen gas tothe fuel cell stack 2103 is terminated upon the fuel cell stack reachinga threshold temperature. In other embodiments, the input and/or outputtemperatures of the fuel cell stack 2103 are monitored so as to activatethe thermal fuse 2130 and automatically shut down the fuel cell stack2103 upon reaching the threshold temperature. Other embodiments canutilize other control systems for safe operation of the hydrogen-poweredfuel cell stacks 2103 and associated electric motors or other powerplants.

The architecture of the compressor-driven fuel cell stacks of thepresent technology provides a configuration in which the fuel cellstacks 2103 are the main power source to the primary electric power unit2114 and associated components of the powertrain 1002 without requiringan intermediate battery. The first and second compressors 2112 and 2108are controlled and activatable to pre-load the fuel cell stacks 2103 inanticipation of one or more predicted power needs. As a result, theconfiguration avoids the need for heavy batteries as well as the needfor heavy DC-to-DC converters, which reduces the complexity, cost, andweight of the fuel cell stack system. For example, in one embodimentwherein the aircraft 10 (FIG. 1) is a dual-motor regional aircraft, theelimination of the conventional DC-to-DC converters is a weight savingsof over approximately 800 kg. Further, the present technology is alsoconfigured to anticipate and predict power needs and the associatedtiming, and the system activates the first and/or second compressors2112 and 2108 to preload the fuel cell stacks 2103 before and duringthose phases of flight where fast transients are required (approach &landing). Operation of the compressors 2112 and 2108 based on actual andpredicted power needs is carefully controlled, so the compressors do notpre-load the fuel cell continuously or excessively, which wouldsignificantly decrease the efficiency of the fuel cell system. Thearchitecture of the powertrain system 1000 is such that it eliminatesthe heavy primary batteries and DC-to-DC converters, and the system onlyutilizes the small peripheral battery 2109 to temporarily provide powerto the fuel cell peripherals during startup of the fuel cell system.This small peripheral start up battery 2109 also only needs a small,light DC-to-DC converter to control the battery's charge/discharge rateand to match the voltage on the powertrain's high voltage bus.

As discussed in greater detail below, the second compressor 2108 iscoupled to the HEATMS 1004 and can be controlled to provide airflow tothe fuel cell stack 2103 at selected volumes and at selected times,depending upon the current or anticipated needs for power output to theelectric power unit 2114. In the illustrated embodiment used with thedual motor aircraft 10, each electric motor is coupled to a plurality offuel cell stacks 2103. For example, each electric motor is coupled toapproximately ten to fourteen hydrogen-powered fuel cell stacks 2103.The second compressor 2108 is controlled so that when an electric motor2114 requires more power, the second compressor 2108 can be controlledby the HEATMS 1004 to increase the airflow to the associated fuel cellstack 2103. The flow rate and volume of airflow from the secondcompressor 2108 to the fuel cell stack 2103 is actively controlled tobalance the fuel cell efficiency, the hydrogen fuel usage, the poweroutput, and the thermal management system so as to achieve the desiredpower output from the associated electric motor 2114 without overdrivingand overheating the fuel cell stack 2103 for an excessive period oftime.

FIG. 4A is a schematic diagram of a fuel cell powertrain architecture2250 in accordance with an embodiment of the present technology. In theillustrated embodiment, the fuel cell stacks 2103 and the powertrainloads 2252, such as the primary power electric unit 2114, the firstcompressor 2112, the small bi-directional DC-DC converter 2254, thecoolant pumps 2101, etc. (FIG. 2), are connected directly to a main highvoltage bus (“HV-bus”) 2256. The voltage output provided from the fuelcell stacks 2103 to the primary electric power unit 2114 is notregulated by the DC-DC converter 2254. The small startup battery 2109 iscoupled to the HV-bus 2256 by the DC-DC converter 2254. Accordingly, thevoltage provided to and from the small startup battery 2109 to theHV-bus 2256 is regulated by the DC-DC converter 2254.

In the illustrated embodiment, the startup battery 2109 is used totemporarily power the powertrain loads 2252 at least until the fuel cellstacks have completed the startup process, as discussed below. Thebidirectional DC-DC converter 2254 controls the battery charge anddischarge rate by matching the HV-bus voltage. Once the fuel cell systemhas started and is generating power, the startup battery 2109 can berecharged. In the illustrated embodiment, the HV-bus 2256 is directlyconnected to the fuel cell stacks 2103 and to the loads 2252. Thecomponents corresponding to the loads 2252 are also directly connectedto the HV-bus 2256 without a large intermediate DC-DC converter. Theseloads 2252 may have a maximum voltage rating less than the maximumvoltage output from the fuel cell stacks 2103, such as during startup ofthe system. Accordingly, the voltage received from the fuel cell stacks2103 is selectively controlled so as to not exceed the voltage that canbe accepted by the components.

FIG. 4B is a graph of the voltage-power per fuel cell stack of the fuelcell powertrain architecture 2250. The fuel cell stack voltage inresponse to the power being drawn from the components connected to theHV-bus 2256 is shown by the curve 2258. In some embodiments, the maximumvoltage level that can be accepted by the loads 2252 connected to theHV-bus 2256, as shown as the dashed line 2260 in the graph, may be lessthan the maximum voltage output from the fuel cell stacks 2103,particularly at startup and before a sufficient amount of power is drawnfrom the HV-bus 2256 by the other loads 2252. For example, in theillustrated embodiment, the voltage on the HV-bus 2256 at startup,generated by the fuel cell stacks 2103 with approximately 0 kW draw onthe bus from other loads 2252, is approximately 974 volts. The maximumvoltage rating of the other loads 2252, however, is approximately 750volts. When the other loads 2252 are activated and power is drawn fromthe HV-bus 2256 by the loads 2252, the voltage level decreases, suchthat the voltage is at or below 750 volts when the power draw is at orabove 30 kW. Accordingly, the voltage to the HV-bus 2256 needs to becontrolled, particularly at startup, at least until the power draw fromthe HV-bus 2256 drops to or below the maximum voltage level that can beaccepted by the loads 2252 (e.g., approximately 750 volts). This isshown by the solid line 2261 in the curve representing the HV busvoltage, which does not exceed 750 volts in the illustrated embodiment.As a result, the loads 2252, such as the primary electric power unit2214, the first compressor 2112, the pumps 2101, the small DC-DCconverter 2254, etc. (FIG. 2) are protected from receiving excessivevoltage during fuel cell stack startup.

The current technology provides a startup sequence that allows the fuelcell stack 2103 and the primary components connected to the HV-bus 2256(i.e., the loads 2252) to power up without exceeding their respectivemaximum voltage rating. FIG. 4C is a voltage-time graph and sequencetable of a startup sequence in accordance with at least one embodimentof the present technology. Steps 1-6 of the startup procedure areidentified in FIG. 4C, and the corresponding voltage on the HV-bus 2256is shown by the curve 2263. In this embodiment, at Step 1 of thestartup, the fuel cell stacks 2103 are temporarily disconnected orisolated from the HV-bus 2256, hydrogen fuel is provided to the fuelcell stacks 2103, and the startup battery 2109 provides power to theHV-bus through the small DC-DC converter 2254, so as to power the pumps2101 and the other loads 2252 on the HV-bus. At Steps 2-3, the startupbattery 2109 provides power to the first air compressor 2112 and otherloads 2252 on the HV-bus 2256. The fuel cell stacks 2103 of theillustrated embodiment are activated and begin generating electricity ata voltage that may exceed the voltage rating of some or all of the loads2252 connected to the HV-bus 2256. At Step 2, when the loads 2252 drawdown the voltage from the HV-bus 2256 to a sufficient level, theactivated fuel cell stacks 2103 are connected to the HV-bus 2256, andthe stack voltage on the bus rises to the maximum controlled stackvoltage, which is still below the maximum rated voltage of the otherloads 2252 on the bus. In the illustrated embodiment that maximum ratedvoltage is 750 volts, but the maximum rated voltage in other embodimentscan be greater or less than 750 volts.

At Steps 3-6, the fuel cell stacks 2103 can provide the regulated, fullpower to the HV-bus 2256 at the selected voltage (e.g., 750 volts) topower to all of the loads 2252 on the bus. In addition, at Steps 5-6,the startup battery 2109 is no longer providing power, and thebi-directional DC-DC converter 2254 is switched so as to recharge thebattery 2109 for use in the next startup sequence. The voltage on theHV-bus 2256 is closely monitored, and in the event the voltage on thebus exceeds a maximum voltage rating of a component on the bus, thevoltage on the bus can be adjusted, the component may be disconnectedfrom the bus, or the fuel cell stack may even be disconnected or thepower output decreased as to properly maintain the electrical balance ofthe system for safe and consistent operation.

In another embodiment, the fuel cell powertrain architecture can beconfigured to control the voltage on the HV-bus 2256. For example, theHV-bus 2256 can include one or more resistive loads in series or inparallel with the fuel cell stacks 2103, so that the resistive loads canbe engaged or disengaged to help control the HV-bus's voltage levels.FIG. 4D is a schematic circuit diagram of a fuel cell powertrainarchitecture 2250 in accordance with at least one embodiment of thepresent technology. In this embodiment, the circuitry of the HV-bus 2256has one or more resistors 2262 arranged in series with the fuel cellstacks 2103 and the loads 2252, so as to effectively provide a voltagedivider between the fuel cell stacks 2103 and the other loads 2252, suchas the primary electric power unit 2114, the air compressor 2112, thecoolant pumps 2101, the DC-DC converter 2254, etc., that may have alower acceptable voltage level than the maximum voltage output from thefuel cell stacks 2103. The HV-bus circuitry also includes switches 2264that can be closed and opened to engage and disengage the resistors 2262during operation of the bus. During the startup procedure when the fuelcell stacks 2103 are activated and the voltage provided to the HV-bus2256 exceeds a selected level (e.g., over 750 volts), the switches 2264are closed to engage the resistor 2262 and reduce the voltage on thebus. When the other loads 2252 draw enough voltage down from the HV-bus2256, the switches 2264 can be opened to disengage the resistor 2262 inthe HV-bus 2256. This disengagement of the resistor 2262 would occur atapproximately Step 2 of the sequence discussed above in connection withFIG. 4C, and the remaining Steps 3-6 of the sequence would remain thesame.

FIG. 4E is a schematic circuit diagram of a fuel cell powertrainarchitecture 2250 in accordance with another embodiment of the presenttechnology. In this embodiment, the HV-bus 2256 has one or moreresistors 2266 arranged in parallel with the fuel cell stacks 2103 andthe other loads 2252 on the bus. Switches 2268 are positioned to so asto engage and disengage the resistor 2266 upon closing or opening theswitches. This parallel configuration can allow for use of one or morededicated resistors 2262 to potentially reduce the complexity of thestartup sequence. During the startup procedure, once the power drawsfrom the other loads 2252 sufficiently draw down the voltage on theHV-bus 2256, the switches 2268 are opened to disengage the resistors2262. This disengagement of the resistors 2262 would occur in Steps 2-3of the startup sequence discussed above in connection with FIG. 4C, andthe remaining Steps 3-6 of the sequence would remain the same.

The circuit diagrams of FIGS. 4D and 4E are examples of only twoembodiments for controlling the voltage on the HV-bus 2256 duringstartup so as to avoid using large and heavy DC-DC converters toregulate the voltage output from the fuel cell stacks 2103 to the bus.Other embodiments can use other circuit configurations that manage thevoltage to or on the HV-bus 2256 to which the other loads 2252 in thepowertrain system can be connected.

FIGS. 5-7 show exemplary rotational speed reducers 2104 and primaryelectric power unit 2114. In some embodiments, the rotational speedreducer 2104 receives power from the primary electric power unit 2114and transmits power to the propeller 2109. In some embodiments, therotational speed reducer 2104 comprises a gearbox, a timing belt, anelectromagnetic clutch, or any combination thereof.

In some embodiments, per FIG. 5, the rotational speed reducer 2104 is aplanetary gearbox 2401. The use of the planetary gearbox 2401 reduces aweight and size of the hydrogen-powered hybrid electric powertrain. Theuse of the planetary gearbox 2401 can increase a stiffness of thehydrogen-powered hybrid electric powertrain and can provide a simplifiedgear reduction stage. The planetary gearbox 2401 comprises high-contactgears, an integrated brake, or both to mitigate propeller 2109 vaning incase of shutdown. The use of the planetary gearbox 2401 provides a lowergear reduction with less mechanical stress. In some embodiments, whenthe rotational speed reducer 2104 comprises the planetary gearbox 2401,an output shaft of the electronic power unit and the rotation of thepropeller 2109 are permanently coupled.

In some embodiments, per FIG. 6, the rotational speed reducer 2104comprises a timing belt 2501. The use of the timing belt 2501 caneliminate a requirement for cooling. The use of the timing belt can alsoreduce the complexity, cost, or both of the rotational speed reducer2104. The use of the timing belt 2501 can reduce weight and stress asspeed reduction and higher torques occur at propeller shaft 2502. Insome embodiments, when the rotational speed reducer 2104 comprises thetiming belt, an output shaft of the electronic power unit and therotation of the propeller shaft 2502 are permanently coupled.

In some embodiments, per FIG. 7, the rotational speed reducer 2104 ofthe hydrogen powered hybrid-electric powertrain 1002 comprises a timingbelt 2501 and an electromagnetic propeller clutch 2503. In someembodiments, when the rotational speed reducer 2104 comprises the timingbelt 2501 and the electromagnetic propeller clutch 2503, an output shaftof the electronic power unit and the rotation of the propeller shaft2502 are decouplable during use. In some embodiments, the configurationof the rotational speed reducer 2104 with the timing belt 2501 and theelectromagnetic propeller clutch 2503 can eliminate or reduce therequirement for cooling. In some embodiments, this configuration canalso provide reduced complexity, cost, or both. The configuration canalso reduce weight and stress as speed reduction and higher torquesoccur at propeller shaft 2502. In some embodiments, this configurationcan also absorb transient outputs from motors and enable decoupling of afailed motor from the drive shaft to eliminate or reduce parasitic drag,while maintaining net power near about 50%. In some embodiments, thepowertrain 1002 does not comprise the rotational speed reducer 2104,wherein the primary electric power unit 2114 provides rotational energyat a sufficiently reduced speed.

In some embodiments, per FIG. 2, ambient and cabin air received by a thefirst compressor 2112 is compressed and provided to the secondcompressor 2108 and the aircraft's cabin air conditioning unit 2202. Insome embodiments, the cabin air conditioning unit 2202 receives and/ortransmits thermal energy to the radiator 2102. The air compressed by thefirst compressor 2112 is further compressed by the second compressor2108, which further receives mechanical energy from the turbine 2104.The air compressed by the second compressor 2108 is transmitted througha humidifier and to a fuel cell stack 2103. The humidifier exchangesthermal energy and coolant with the radiator 2102 and provides coolant(e.g., water-ethylene glycol, or a combination thereof) to the coolantpump 2101 through the closed circuit piping, wherein the coolant flowingin the piping receives thermal energy from the coolant pump.

The fuel cell stack 2103 receives hydrogen from hydrogen piping 2208 andreceives the coolant that is pumped via the coolant pump 2101 to carrythe heat energy to the radiator 2102. The fuel cell stack 2103 provideselectrical energy to the coolant pump 2101, the peripheral power unit2110, and the primary electric power unit 2114. In some embodiments, theperipheral power unit 2110 exchanges oil or other coolant with thecoolant pump 2101 and provides thermal energy to the one or moreradiators 2102. The peripheral power unit 2110 can provide mechanicalenergy to the first compressor 2112 and to peripheral aircraftcomponents 2111, such as hydraulic pumps, avionics, a deicing system,and a galley. In some embodiments, the electric power unit 2114exchanges oil or other coolant in the associated coolant circuit withthe coolant pump, provides thermal energy to the radiator 2102, andprovides mechanical power to a gearbox 2212. The gearbox 2212 exchangesoil or other coolant with the coolant pump 2101, provides thermal energyto the coolant pump 2101, and provides mechanical power to a propeller2116.

Computer Hydro-Electro-Aero-Thermal Management System (HEATMS)

During use of the aircraft 10 (FIG. 1) with its powertrain system 1000,the system components typically require different amounts of accessiblepower during different stages of use. For example, the aircraft'scomponents typically need different levels of available power duringstartup, taxi, takeoff, climb, cruise, intra-flight maneuvers ormodifications, descent, landing, and shutdown. Embodiments of thepresent technology are configured to control the thermally managedpowertrain system 1000 to accurately and consistently provide therequired power level in a timely manner by monitoring and controllingthe system with the HEATMS 1004. The HEATMS 1004 can be monitored andcontrolled via one or more computer system, such as a controller 2302(FIG. 2), using non-transitory computer-readable storage media encodedwith a computer program including instructions executable by a processorto create, operate, or run a HEATMS application 2300. In someembodiments, as schematically illustrated in FIG. 8, the HEATMSapplication 2300 can comprise a first sensor data module 2304 receivingsensor data from sensors 2306 that may be onboard the aircraft 10(FIG. 1) and/or external or remote from the aircraft. A second powercontrol module 2308 is coupled to the first module 2304 to receive thesensor data and to determine based on the sensor data, a peripheralelectric power output; a primary electric power output; a battery poweroutput, a pump power, a pump fluid flowrate, or any combination of theforegoing.

In some embodiments, the sensor data module 2304 is coupled to multiplesensors 2306 (e.g. piezoelectric, optical, radio, or other sensors)and/or components of the aircraft, and the sensed data receivedcomprises, as an example, ambient air temperature, ambient air pressure,aircraft velocity, aircraft altitude, aircraft GNSS position, peripheralelectric power unit output voltage, peripheral electric power unitoutput current, air inlet flow rate, air inlet temperature, air inletpressure, air/water outlet flow rate, air/water outlet temperature,air/water outlet pressure, hydrogen inlet flow rate, hydrogen inlettemperature, hydrogen inlet pressure, speed reducer temperature,compressor inlet flow rate, compressor inlet temperature, compressorinlet pressure, compressor outlet flow rate, compressor outlettemperature, compressor outlet pressure, turbine inlet flow rate,turbine inlet temperature, turbine inlet pressure, turbine outlet flowrate, turbine outlet temperature, turbine outlet pressure, propellerrotational speed, radiator cooling fluid inlet temperature, radiatorcooling fluid outlet temperature, Flight Management System (FMS) flightpath, Flight Management System (FMS) status, or any combination thereof.In some embodiments, the module determines the peripheral electric poweroutput, the primary electric power output, the battery power output, thepump power, the pump fluid flowrate, a pilot control, or any combinationthereof from the sensor data, which may include sensor data by one ormore machine learning algorithm.

In some embodiments, per FIG. 9, the HEATMS application 2300 can have apredictive module 2310 coupled to the first sensor data module 2304 andthe power control module 2308, wherein the predictive module 2310 isconfigured to determine predicted flight events based on the senseddata. In some embodiments, the predictive module 2310 of the HEATMSapplication 2300 determines one or more predicted flight events from thesensed data by a machine learning algorithm. For example, as seen inFIG. 10, the predictive module 2310 can be configured to receive at 2320the sensed data from the sensor data module, and provide the sensed datato a training dataset at 2322 and to a testing dataset at 2324. Thetraining dataset is provided to the machine learning algorithm at 2326for analysis, which provides the results for evaluation at 2328. Thetesting dataset is also provided to the machine learning algorithm forevaluation at 2328. The machine learning algorithm then outputs a modelat 2320, which also receives production data at 2332, and the modeloutputs one or more predicted flight events at 2334. This predictionoutput can be used by the HEATMS application 2300 for control of thepowertrain components. For example, the HEATMS application 2300 candetermine the peripheral electric power output, the primary electricpower output, the battery power output, the pump power, the pump fluidflowrate, or any combination thereof based on the predicted flightevent. In some embodiments, the predicted flight event is a startupevent, a taxi event, a takeoff event, a cruise event, a climb event, adescent event, a landing event, a shutdown event, or any combinationthereof.

Per FIG. 11, the HEATMS application 2300 predicts a taxi event 3001, atake-off event 3002, a cruise event 3003, a climb event 3004, a descentevent 3005, a landing event 3006, and a stop event 3007 based on thesensed data. In addition to predicting the event, the HEATMS application2300 also predicts, based on the data sensed from the sensors thecurrent power consumption, the anticipated power needs of the associatedaircraft components or systems, and/or the timing of the power needsrelated to the current or predicted event. In some embodiments, once atake-off event 3002 is predicted, the HEATMS application 2300 begins ananticipated take-off procedure 3010 of increasing air flow rate to fuelcell stacks 2103. In some embodiments, once a climb event 3004 ispredicted, the HEATMS application 2300 begins an anticipated climbprocedure 3020 of increasing air flow rate to fuel cell stacks 2103. Insome embodiments, once a landing event 3006 is predicted, the HEATMSapplication 2300 begins an anticipated landing procedure 3030 ofincreasing air flow rate to fuel cell stacks. The HEATMS application2300 can also use other sensed system or component data and/orenvironmental data, operational data, etc., that can affect power needsand power usage in order to define the specific sequence or aspects ofthe anticipated procedure. In some embodiments, a procedure comprisesone or more of the peripheral electric power outputs, the primaryelectric power output, the battery power output, the pump power, or thepump fluid flowrate.

In some embodiments, the HEATMS application 2300 increases a fluid flowrate entering the fuel cell stacks 2103 to increase its electrical poweroutput based on immediate power needs and/or on the anticipated powerneeds predicted by the application. In some embodiments, to increase thefluid flow rate to the fuel cell stacks 2103, the HEATMS application2300 increases the mechanical power transmitted to the first compressor2112, the second compressor 2108, or both. In some embodiments, thefirst compressor 2112, the second compressor 2108, or both receiveincreased power based on an amount of power provided by the battery2109, the peripheral electrical power unit 2110, or both. In someembodiments, the HEATMS application 2300 increases the amount of powerprovided by the battery 2109, the peripheral electrical power unit 2110,or both to increase the mechanical power transmitted to the firstcompressor 2112, the second compressor 2108, or both to increase a fluidflow rate entering the fuel cell stacks 2103 at a sufficiently fast rateto reduce any lag in electrical power output.

The HEATMS application 2300 can anticipate increases in the requiredfuel cell stack's electrical power output and controls the mechanicalpower transmitted to the first compressor 2112, the battery 2109, theperipheral electrical power unit 2110, or any combination thereof, toreduce the electrical power output lag. When the electrical power outputof the fuel cell stacks 2103 is constant or predicted to be constant, itcharges the battery 2109.

In some embodiments, the exhaust water or other fluid passing throughthe turbine 2104, the fuel cell stack 2103, or both may be released intothe atmosphere, such as by spraying the exhaust water onto the radiator2102 for evaporative cooling, as discussed above. Alternatively, theexhaust water or other exhaust fluid may be released through the exhaust2107 of the fluid subsystem 2106 (FIG. 2). However, under certainatmospheric conditions, such an exhaust can form contrails, which arethought to contribute to global warming, such that prevention ofcontrails is desirable. Accordingly, the HEATMS application 2300 can beconfigured to determine the current and/or anticipated environmental,operational, and/or atmospheric conditions in which the aircraft will beoperating, and to direct such fluid to the exhaust 2107 when theapplication determines, based at least in part on the anticipatedenvironmental, operational, and/or atmospheric conditions, thatcontrails will not form. When the HEATMS application 2300 determinesbased at least in part on the anticipated environmental, operational,and/or atmospheric conditions that contrails will likely form, theapplication is configured to provide instructions to the waterdistribution system discussed above to activate the valves to block theexhaust water from the spray bar 2121 and to direct the exhaust fluid toa storage tank 2050 of the fluid storage subsystem 2106 for temporarystorage, at least until the contrail conditions are no longer detected.In some embodiments, the HEATMS application 2300 can direct the fluidstorage to release the fluid to the exhaust 2107 once non-contrailforming atmospheric conditions are detected. The HEATMS application isalso configured to optimize the use of exhaust water not only to avoidcontrails and for deicing, but also to maximize cooling performance bybeing able to temporarily store exhaust water when cooling demand islow, such as during a descent, such that the stored exhaust water cansupplement the exhaust water generated in real time during an event whencooling demand is high, such as during a takeoff.

In some embodiments, the exhaust water and/or heated air or other fluidtransmitted by fuel cell stack 2103, the turbine 2104, or both typicallyhas a temperature in the range of about 65° C. and 85° C. In someembodiments, the HEATMS application 2300 determines the fluidtemperature and other operational, environmental, or atmosphericconditions in which the aircraft is projected or anticipated to beoperating, and the HEATMS application 2300 can direct some or a portionof the heated fluid to the spray bar 2121 and/or to one or more selectedperipheral aircraft systems or components. For example, when the HEATMSapplication 2300 determines and/or predicts that the aircraft will beoperating in conditions that can cause ice formation on the leadingedges of the wings or other lift surfaces, the HEATMS application 2300can activate the controller 2302 to direct the heated fluid from thefuel cell stack 2103, the turbine 2104, or both through a deicing systemin the leading edge portion of the wings or other lift surface so as todeice the surface, or to prevent ice formation, or both. Such iceformation prevention can replace alternative dedicated conventionaldeicing components that would require electrical energy and add weightto a conventional aircraft system. In some embodiments, some or all ofthe heated exhaust water and the heated air generated by the fuel cellstack 2103 and the turbine 2104 can be directed to different portions orcomponents of the aircraft. For example, heated exhaust water can bedirected to the spray bars 2121 and other heated air can be captured anddirected to one or more portions of the aircraft's deicing system.

In some embodiments, the HEATMS application 2300 can be configured toalter an amount of power transmitted to the peripheral electric powerunit based on, for example, a motor rpm, motor torque, input voltage,input current, system temperature, or any combination thereof. In someembodiments, the HEATMS application can be configured to alter an amountof power transmitted to the primary electric power unit 2114 based on amotor rpm, motor torque, input voltage, input current, systemtemperature, or any combination thereof, and the current and/orpredicted operating conditions and power needs of the aircraft'spowertrain and other components.

Vehicles Comprising the Electro-Hydro-Thermal Management System

Another aspect provided herein, per FIG. 8, is a vehicle 2700 comprisingthe fuel cell stack 2102, the electric power unit 2103, the firstcompressor 2112, the second compressor 2108, and the peripheral powerunit 2110. In some embodiments, the vehicle 2700 further comprises anelectric motor inverter 2701. In some embodiments, the vehicle 2700further comprises a radiator 2702. In some embodiments, the vehicle 2700further comprises an auxiliary battery 2703. In some embodiments, thevehicle 2700 is an airplane.

The one or more vehicles may comprise, for example, airplanes and/oraircraft. The aircraft may comprise civilian turbojet aircraft of anysize or category, e.g., wide-body turbojet aircraft, narrow-bodyturbojet aircraft, regional turbojet aircraft, and/or business turbojetaircraft. The aircraft may comprise civilian turboprop or piston poweredaircraft of any size or category, e.g., regional turboprop and pistonpowered aircraft, commuter turboprop and piston powered aircraft, and/orany other type of turboprop or piston powered aircraft. The aircraft maycomprise military turbojet aircraft of any size or category, or militaryturboprop and piston powered aircraft of any size or category. Theaircraft may comprise aircraft configured for long-haul flights,medium-haul flights, and/or short-haul flights. In some cases, theaircraft may comprise, for example, commercial airplanes such as jumbopassenger jets, mid-size passenger jets, light passenger jets, passengerturboprops, and/or cargo airplanes. In other cases, the aircraft maycomprise private jets including, for example, very light jets, lightbusiness jets, mid-size business jets, heavy business jets, or militaryjets. Alternatively, the aircraft may comprise private single engineplanes, twin turboprop planes, aerobatic planes, or amphibious planes.In some cases, the aircraft may comprise a vertical takeoff and landing(VTOL) aircraft. In other cases, the aircraft may comprise one or moreair taxis. The systems and methods of the present disclosure can bemodified and/or adapted for use with any type of aircraft or aerialvehicle.

In some embodiments, the aircraft may comprise a rotorcraft such as ahelicopter. The rotorcraft may be a multi-rotor craft that may include aplurality of rotors. The plurality of rotors may be capable of rotatingto generate lift for the rotorcraft. The rotors may be propulsion unitsthat may enable the rotorcraft to move about freely through the air. Therotors may rotate at the same rate and/or may generate the same amountof lift or thrust. The rotors may optionally rotate at varying rates,which may generate different amounts of lift or thrust and/or permit therotorcraft to rotate. In some instances, one, two, three, four, five,six, seven, eight, nine, ten, or more rotors may be provided on arotorcraft. The rotors may be arranged so that their axes of rotationare parallel to one another. In some instances, the rotors may have axesof rotation that are at any angle relative to one another, which mayaffect the motion of the rotorcraft.

The aircraft may be manned (i.e., operated by a passenger on or in theaircraft). The aircraft may be unmanned (i.e., operated by an individualwho is not on or in the aircraft). The aircraft may be autonomous orsemi-autonomous. The aircraft may be capable of responding to commandsfrom a remote controller. The remote controller may not and need not bephysically connected to the aircraft, and may communicate with theaircraft wirelessly from a distance. The aircraft may be capable ofoperating autonomously or semi-autonomously. The aircraft may be capableof following a set of pre-programmed instructions. The aircraft mayoperate semi-autonomously by responding to one or more commands from aremote controller while otherwise operating autonomously. For instance,one or more commands from a remote controller may initiate a sequence ofautonomous or semi-autonomous actions by the aircraft in accordance withone or more parameters.

In some cases, the one or more vehicles 2000 may comprise a land-bound,underground, underwater, water surface, aerial, or space-based vehicle.The one or more vehicles 2000 may be configured to move within anysuitable environment, such as in air (e.g., a fixed-wing aircraft, arotary-wing aircraft, or an aircraft having neither fixed wings norrotary wings such as a hot air balloon or a blimp), in water (e.g., aship or a submarine), on ground (e.g., a motor vehicle, such as a car,truck, bus, van, motorcycle, bicycle, or a train), underground (e.g., asubway), in space (e.g., a spaceplane, a satellite, or a probe), or anycombination of these environments.

The one or more vehicles may be capable of moving freely within theenvironment with respect to six axes of freedom (e.g., three axes offreedom in translation and three axes of freedom in rotation).Alternatively, the movement of the one or more vehicles can beconstrained with respect to one or more axes of freedom, such as by apredetermined path, track, or orientation. The movement can be actuatedby any suitable actuation mechanism, such as an engine, a motor, or ahydrogen electric propulsion system as described below. The actuationmechanism of the one or more vehicles can be powered by any suitableenergy source, such as hydrogen, or any energy source derivable fromhydrogen, such as electrical energy. The one or more vehicles may beself-propelled via a propulsion system, as described elsewhere herein.

In some instances, the one or more vehicles may be self-propelled, suchas self-propelled through the air, on or in water, in space, or on orunder the ground. A self-propelled vehicle can utilize a propulsionsystem, such as a propulsion system including one or more engines,motors, wheels, axles, magnets, rotors, propellers, blades, nozzles, orany suitable combination thereof. The propulsion system can be used toenable the one or more vehicles to take off from a surface, land on asurface, maintain its current position and/or orientation (e.g., hover),change orientation, and/or change position.

The propulsion system may comprise one or more propulsion mechanisms.The one or more propulsion mechanisms may comprise one or more ofrotors, propellers, blades, engines, motors, wheels, axles, magnets, ornozzles. The vehicles described herein may have one or more, two ormore, three or more, or four or more propulsion mechanisms. Thepropulsion mechanisms may all be of the same type. Alternatively, one ormore propulsion mechanisms can be different types of propulsionmechanisms. The propulsion mechanisms can be mounted on the vehicleusing any suitable means. The propulsion mechanisms can be mounted onany suitable portion of the vehicle, such as on the top, bottom, front,back, sides, or suitable combinations thereof.

In some embodiments, the propulsion mechanisms can enable the vehicle2000 to take off vertically from a surface or land vertically on asurface without requiring any horizontal movement of the vehicle (e.g.,without traveling down a runway). The movement of the one or morevehicles can be actuated by any suitable actuation mechanism, such as anengine or a motor. The actuation mechanism of the one or more vehiclescan be powered by any suitable energy source, such as electrical energygenerated using one or more fuel cells. The vehicle may beself-propelled via the propulsion system. One or more of the propulsionmechanisms may be controlled independently of the other propulsionmechanisms. Alternatively, the propulsion mechanisms can be configuredto be controlled simultaneously.

The one or more vehicles can be controlled remotely by a user orcontrolled locally by an occupant within or on the one or more vehicles.In some embodiments, the one or more vehicles may be an unmanned movableobject, such as a UAV. The unmanned movable object, such as a UAV, maynot have an occupant onboard the unmanned movable object. The unmannedmovable object can be controlled by a human or an autonomous controlsystem (e.g., a computer control system), or any suitable combinationthereof. The unmanned movable object can be an autonomous orsemi-autonomous robot, such as a robot configured with an artificialintelligence.

The one or more vehicles can have any suitable size and/or dimensions.In some embodiments, the one or more vehicles may be of a size and/ordimensions to have a human occupant within or on the vehicle.Alternatively, the one or more vehicles may be of size and/or dimensionssmaller than that capable of having a human occupant within or on thevehicle. In some instances, the one or more vehicles may have a maximumdimension (e.g., length, width, height, diameter, diagonal) that isabout 1 m, 2 m, 3 m, 4 m, 5 m, 10 m, 20 m, 30 m, 40 m, 50 m, or greater.In some embodiments, the one or more vehicles can be configured to carrya load. The load can include one or more passengers, cargo, equipment,instruments, fuel storage modules, and the like.

Computer Systems

FIG. 12 shows a computer system 2001 that is programmed or otherwiseconfigured to implement a method for carbon-free transportation. Themethod may comprise determining a demand for hydrogen fuel storagemodules and coordinating a delivery or a transportation of one or morehydrogen fuel storage modules to one or more hydrogen fuel compatiblevehicles located at or near one or more vehicle fueling sites. Thecomputer system 2001 can be an electronic device of a user or a computersystem that is remotely located with respect to the electronic device.The electronic device can be a mobile electronic device.

The computer system 2001 may include a central processing unit (CPU,also “processor” and “computer processor” herein) 2005, which can be asingle core or multi core processor, or a plurality of processors forparallel processing. The CPU 2005 or other portion of the computersystem 2001 of one or more embodiments also has a real-time operatingsystem configured execute instructions at defined times and in order.The computer system 2001 also includes memory or memory location 2010(e.g., random-access memory, read-only memory, flash memory), electronicstorage unit 2015 (e.g., hard disk), communication interface 2020 (e.g.,network adapter) for communicating with one or more other systems, andperipheral devices 2025, such as cache, other memory, data storageand/or electronic display adapters. The memory 2010, storage unit 2015,interface 2020, and peripheral devices 2025 are in communication withthe CPU 2005 through a communication bus (solid lines), such as amotherboard. The storage unit 2015 can be a data storage unit (or datarepository) for storing data. The computer system 2001 can beoperatively coupled to a computer network (“network”) 2030 with the aidof the communication interface 2020. The network 2030 can be theInternet, an internet and/or extranet, or an intranet and/or extranetthat is in communication with the Internet. The network 2030 in somecases is a telecommunication and/or data network. The network 2030 caninclude one or more computer servers, which can enable distributedcomputing, such as cloud computing. The network 2030, in some cases withthe aid of the computer system 2001, can implement a peer-to-peernetwork, which may enable devices coupled to the computer system 2001 tobehave as a client or a server.

The CPU 2005 can execute a sequence of machine-readable instructions,which can be embodied in a program or software. The instructions may bestored in a memory location, such as the memory 2010. The instructionscan be directed to the CPU 2005, which can subsequently program orotherwise configure the CPU 2005 to implement methods of the presentdisclosure. Examples of operations performed by the CPU 2005 can includefetch, decode, execute, and writeback.

The CPU 2005 can be part of a circuit, such as an integrated circuit.One or more other components of the system 2001 can be included in thecircuit. In some cases, the circuit is an application specificintegrated circuit (ASIC).

The storage unit 2015 can store files, such as drivers, libraries andsaved programs. The storage unit 2015 can store user data, e.g., userpreferences and user programs. The computer system 2001 in some casescan include one or more additional data storage units that are locatedexternal to the computer system 2001 (e.g., on a remote server that isin communication with the computer system 2001 through an intranet orthe Internet).

The computer system 2001 can communicate with one or more remotecomputer systems through the network 2030. For instance, the computersystem 2001 can communicate with a remote computer system of a user(e.g., an operator of a hydrogen fuel compatible vehicle, an operator ofa transport vehicle for transporting one or more hydrogen fuel storagemodules, a technician at a hydrogen production facility, an entitymanaging a just-in-time network for hydrogen fuel cell delivery anddistribution, etc.). Examples of remote computer systems includepersonal computers (e.g., portable PC), slate or tablet PC's (e.g.,Apple® iPad, Samsung® Galaxy Tab), telephones, Smart phones (e.g.,Apple® iPhone, Android-enabled device, Blackberry®), or personal digitalassistants. The user can access the computer system 2001 via the network2030.

Methods as described herein can be implemented by way of machine (e.g.,computer processor) executable code stored on an electronic storagelocation of the computer system 2001, such as, for example, on thememory 2010 or electronic storage unit 2015. The machine executable ormachine readable code can be provided in the form of software. Duringuse, the code can be executed by the processor 2005. In some cases, thecode can be retrieved from the storage unit 2015 and stored on thememory 2010 for ready access by the processor 2005. In some situations,the electronic storage unit 2015 can be precluded, andmachine-executable instructions are stored on memory 2010.

The code can be pre-compiled and configured for use with a machinehaving a processor adapted to execute the code or can be compiled duringruntime. The code can be supplied in a programming language that can beselected to enable the code to execute in a pre-compiled or as-compiledfashion.

Aspects of the systems and methods provided herein, such as the computersystem 2001, can be embodied in programming. Various aspects of thetechnology may be thought of as “products” or “articles of manufacture”typically in the form of machine (or processor) executable code and/orassociated data that is carried on or embodied in a type of machinereadable medium. Machine-executable code can be stored on an electronicstorage unit, such as memory (e.g., read-only memory, random-accessmemory, flash memory) or a hard disk. “Storage” type media can includeany or all of the tangible memory of the computers, processors or thelike, or associated modules thereof, such as various semiconductormemories, tape drives, disk drives and the like, which may providenon-transitory storage at any time for the software programming. All orportions of the software may at times be communicated through theInternet or various other telecommunication networks. Suchcommunications, for example, may enable loading of the software from onecomputer or processor into another, for example, from a managementserver or host computer into the computer platform of an applicationserver. Thus, another type of media that may bear the software elementsincludes optical, electrical, and electromagnetic waves, which may betransmitted across physical interfaces between local devices, throughwired and optical landline networks and over various air-links. Thephysical elements that carry such waves, such as wired or wirelesslinks, optical links or the like, also may be considered as mediabearing the software. As used herein, unless restricted tonon-transitory, tangible “storage” media, terms such as computer ormachine “readable medium” refer to any medium that participates inproviding instructions to a processor for execution.

Hence, a machine readable medium, such as computer-executable code, maytake many forms, including but not limited to, a tangible storagemedium, a carrier wave medium, or physical transmission medium.Non-volatile storage media including, for example, optical or magneticdisks, or any storage devices in any computer(s) or the like, may beused to implement the databases, etc. shown in the drawings. Volatilestorage media include dynamic memory, such as main memory of such acomputer platform. Tangible transmission media include coaxial cables;copper wire and fiber optics, including the wires that comprise a buswithin a computer system. Carrier-wave transmission media may take theform of electric or electromagnetic signals, or acoustic or light wavessuch as those generated during radio frequency (RF) and infrared (IR)data communications. Common forms of computer-readable media thereforeinclude, for example: a floppy disk, a flexible disk, hard disk,magnetic tape, any other magnetic medium, a CD-ROM, DVD or DVD-ROM, anyother optical medium, punch cards, paper tape, any other physicalstorage medium with patterns of holes, a RAM, a ROM, a PROM and EPROM, aFLASH-EPROM, any other memory chip or cartridge, a carrier wavetransporting data or instructions, cables or links transporting such acarrier wave, or any other medium from which a computer may readprogramming code and/or data. Many of these forms of computer readablemedia may be involved in carrying one or more sequences of one or moreinstructions to a processor for execution.

The computer system 2001 can include or be in communication with anelectronic display 2035 that comprises a user interface (UI) 2040 forproviding, for example, a portal for monitoring a transportation or ausage of one or more hydrogen fuel storage modules. The portal may beprovided through an application programming interface (API). A user orentity can also interact with various elements in the portal via the UI.Examples of UI's include, without limitation, a graphical user interface(GUI) and web-based user interface.

Databases

In some embodiments, the platforms, systems, media, and methodsdisclosed herein include one or more databases, or use of the same. Inview of the disclosure provided herein, those of skill in the art willrecognize that many databases are suitable for storage and retrieval offlight data, weather data, trajectory data, performance curves, or anyother aerial information. In various embodiments, suitable databasesinclude, by way of non-limiting examples, relational databases,non-relational databases, object-oriented databases, object databases,entity-relationship model databases, associative databases, and XMLdatabases. Further non-limiting examples include SQL, PostgreSQL, MySQL,Oracle, DB2, and Sybase. In some embodiments, a database isinternet-based. In further embodiments, a database is web-based. Instill further embodiments, a database is cloud computing-based. In aparticular embodiment, a database is a distributed database. In otherembodiments, a database is based on one or more local computer storagedevices.

Machine Learning

In some embodiments, machine learning algorithms are utilized to aid indetermining how much heat, water, coolant, oil, or any combinationthereof to provide to the components of the thermally managed powertrainsystems 1000. In some embodiments, machine learning algorithms areutilized to aid in determining at what speed or gear ratio to run thecomponents of the thermally managed powertrain systems 1000. In someembodiments, machine learning algorithms employ an altitude, a speed, anexternal temperature, an internal temperature, or any combinationthereof to determine the optimal operational parameters of the thermallymanaged powertrain systems 1000. In some embodiments, the machinelearning algorithm is used to optimize the performance of the powertrain1002 and/or the HEATMS 1004.

In some embodiments, the machine learning algorithms herein are taughtbased on data collected when testing the thermally managed powertrainsystems 1000 or components thereof, one or more forms of labels,including but not limited to, human annotated labels and semi-supervisedlabels, distant supervision, regression modeling, or any combinationthereof. The human annotated labels can be provided by a hand-craftedheuristic. The semi-supervised labels can be determined using aclustering. The semi-supervised labels can employ a XGBoost, a neuralnetwork, or both.

The distant supervision method can create a large training set seeded bya small hand-annotated training set. The distant supervision method cancomprise positive-unlabeled learning with the training set as the‘positive’ class. The distant supervision method can employ a logisticregression model, a recurrent neural network, or both. The recurrentneural network can be advantageous for Natural Language Processing (NLP)machine learning.

Examples of machine learning algorithms can include a support vectormachine (SVM), a naïve Bayes classification, a random forest, a neuralnetwork, deep learning, or other supervised learning algorithm orunsupervised learning algorithm for classification and regression. Themachine learning algorithms can be trained using one or more trainingdatasets.

In some embodiments, the machine learning algorithm utilizes regressionmodeling, wherein relationships between predictor variables anddependent variables are determined and weighted.

In some embodiments, a machine learning algorithm is used to selectcatalogue images and recommend project scope. A non-limiting example ofa multi-variate linear regression model algorithm is seen below:probability=A0+A1 (X1)+A2(X2)+A3(X3)+A4(X4)+A5(X5)+A6(X6)+A7(X7) . . .wherein Ai (A1, A2, A3, A4, A5, A6, A7, . . . ) are “weights” orcoefficients found during the regression modeling; and Xi (X1, X2, X3,X4, X5, X6, X7, . . . ) are data collected from the User. Any number ofAi and Xi variable can be included in the model. In some embodiments,the programming language “R” is used to run the model.

In some embodiments, training comprises multiple steps. In a first step,an initial model is constructed by assigning probability weights topredictor variables. In a second step, the initial model is used to“recommend” performance characteristics. At least one of the first step,the second step, and the third step can repeat one or more timescontinuously or at set intervals.

Terms and Definitions

Unless otherwise defined, all technical terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this disclosure belongs.

The term “real time,” as used herein, generally refers to a simultaneousor substantially simultaneous occurrence of a first event or action withrespect to an occurrence of a second event or action. A real time actionor event may be performed within a response time of less than one ormore of the following: ten seconds, five seconds, one second, a tenth ofa second, a hundredth of a second, a millisecond, or less relative to atleast another event or action. A real-time action may be performed byone or more computer processors.

Whenever the term “at least,” “greater than,” or “greater than or equalto” precedes the first numerical value in a series of two or morenumerical values, the term “at least,” “greater than,” or “greater thanor equal to” applies to each of the numerical values in that series ofnumerical values. For example, greater than or equal to 1, 2, or 3 isequivalent to greater than or equal to 1, greater than or equal to 2, orgreater than or equal to 3.

Whenever the term “no more than,” “less than,” or “less than or equalto” precedes the first numerical value in a series of two or morenumerical values, the term “no more than,” “less than,” or “less than orequal to” applies to each of the numerical values in that series ofnumerical values. For example, less than or equal to 3, 2, or 1 isequivalent to less than or equal to 3, less than or equal to 2, or lessthan or equal to 1.

As used herein, the singular forms “a,” “an,” and “the” include pluralreferences unless the context clearly dictates otherwise. Any referenceto “or” herein is intended to encompass “and/or” unless otherwisestated.

As used herein, the term “about” in some cases refers to an amount thatis approximately the stated amount.

As used herein, the term “about” refers to an amount that is near thestated amount by 10%, 5%, or 1%, including increments therein.

As used herein, the term “about” in reference to a percentage refers toan amount that is greater or less than the stated percentage by 10%, 5%,or 1%, including increments therein.

As used herein, the phrases “at least one”, “one or more,” and “and/or”are open-ended expressions that are both conjunctive and disjunctive inoperation. For example, each of the expressions “at least one of A, B,and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “oneor more of A, B, or C” and “A, B, and/or C” means A alone, B alone, Calone, A and B together, A and C together, B and C together, or A, B andC together.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. It is not intendedthat the invention be limited by the specific examples provided withinthe specification. While the invention has been described with referenceto the aforementioned specification, the descriptions and illustrationsof the embodiments herein are not meant to be construed in a limitingsense. Numerous variations, changes, and substitutions will now occur tothose skilled in the art without departing from the invention.Furthermore, it shall be understood that all aspects of the inventionare not limited to the specific depictions, configurations or relativeproportions set forth herein which depend upon a variety of conditionsand variables. It should be understood that various alternatives to theembodiments of the invention described herein may be employed inpracticing the invention. It is therefore contemplated that theinvention shall also cover any such alternatives, modifications,variations, or equivalents. It is intended that the following claimsdefine the scope of the invention and that methods and structures withinthe scope of these claims and their equivalents be covered thereby.

We claim:
 1. A method for optimizing operation of an aerial vehiclehaving a hydrogen-powered hybrid electric powertrain, the methodcomprising: providing hydrogen fuel to one or more fuel cell stacks;directing a first amount of air to the one or more fuel cell stackspowered by the hydrogen fuel and generating a first output of electricalpower for use at least by an electric motor of the hydrogen-poweredhybrid electric powertrain; operating the electric motor using thegenerated electrical power, wherein the generated electrical power isprovided to the electric motor without passing through a DC-to-DCconverter and/or being stored in a battery; predicting one or morechanges in an electrical power demand of the powertrain during operationof the electric motor; controlling an amount of air flow to the one ormore fuel cell stacks to direct a second amount of air to the one ormore fuel cell stacks based at least in part on the one or morepredicted changes in the electrical power demand of the powertrain,wherein the first amount of air is different than the second amount ofair provided to the one or more fuel cell stacks; and providing thesecond amount of air to the one or more fuel cell stacks beforeoccurrence of the predicted electrical power demand for generation of asecond output of electrical power by the one or more fuel cell stacks ator before occurrence of the predicted electrical power demand of thepowertrain, wherein the second output of electrical power is differentthan the first output of electrical power, thereby reducing a transientperiod for delivery of the electrical power to the electric motor of thepowertrain; wherein predicting one or more changes in an electricalpower demand of the powertrain is based at least in part on one or moreof the following: one or more inputs from a pilot of the aerial vehicle;a current, previous, or next position of the aerial vehicle; a flightpath comprising a plurality of spatial coordinates; or atmosphericweather conditions.
 2. The method of claim 1 wherein the amount of airflow is controlled in part by controlling mechanical power to one ormore compressors that direct airflow toward the one or more fuel cellstacks.
 3. The method of claim 2 wherein the one or more compressors arepowered at least partially by a peripheral electrical power unit.
 4. Themethod of claim 1 wherein the second amount of air is provided to theone or more fuel cell stacks at a time so the one or more fuel cellstacks provides sufficient electrical power to meet the predictedelectrical power demand before the occurrence of the predicted demand ofthe electrical power output.
 5. A method for optimizing operation of anaerial vehicle having a hydrogen-powered hybrid electric powertrain, themethod comprising: providing hydrogen fuel to one or more fuel cellstacks; directing a first amount of air to the one or more fuel cellstacks powered by the hydrogen fuel and generating a first output ofelectrical power for use at least by an electric motor of thehydrogen-powered hybrid electric powertrain; operating the electricmotor using the generated electrical power, wherein the generatedelectrical power is provided to the electric motor without passingthrough a DC-to-DC converter and/or being stored in a battery;predicting one or more changes in an electrical power demand of thepowertrain during operation of the electric motor; controlling an amountof air flow to the one or more fuel cell stacks to direct a secondamount of air to the one or more fuel cell stacks based at least in parton the one or more predicted changes in the electrical power demand ofthe powertrain, wherein the first amount of air is different than thesecond amount of air provided to the one or more fuel cell stacks; andproviding the second amount of air to the one or more fuel cell stacksbefore occurrence of the predicted electrical power demand forgeneration of a second output of electrical power by the one or morefuel cell stacks at or before occurrence of the predicted electricalpower demand of the powertrain, wherein the second output of electricalpower is different than the first output of electrical power, therebyreducing a transient period for delivery of the electrical power to theelectric motor of the powertrain wherein the one or more fuel cellstacks and the electric motor are coupled to one or more radiators fordissipating heat generated at least by the one or more fuel cell stacksand the electric motor, and wherein the one or more fuel cell stacksgenerate exhaust water when generating the electrical power, the methodfurther comprises applying the exhaust water to the one or moreradiators for evaporative cooling for dissipation of the heat generatedat least by the one or more fuel cell stacks and the electric motor. 6.The method of claim 5 wherein applying exhaust water to the one or moreradiators comprises spraying the exhaust water onto the one or moreradiators.
 7. A method for optimizing operation of an aerial vehiclehaving a hydrogen-powered hybrid electric powertrain, the methodcomprising: providing hydrogen fuel to one or more fuel cell stacks;directing a first amount of air to the one or more fuel cell stackspowered by the hydrogen fuel and generating a first output of electricalpower for use at least by an electric motor of the hydrogen-poweredhybrid electric powertrain; operating the electric motor using thegenerated electrical power, wherein the generated electrical power isprovided to the electric motor without passing through a DC-to-DCconverter and/or being stored in a battery; predicting one or morechanges in an electrical power demand of the powertrain during operationof the electric motor; controlling an amount of air flow to the one ormore fuel cell stacks to direct a second amount of air to the one ormore fuel cell stacks based at least in part on the one or morepredicted changes in the electrical power demand of the powertrain,wherein the first amount of air is different than the second amount ofair provided to the one or more fuel cell stacks; providing the secondamount of air to the one or more fuel cell stacks before occurrence ofthe predicted electrical power demand for generation of a second outputof electrical power by the one or more fuel cell stacks at or beforeoccurrence of the predicted electrical power demand of the powertrain,wherein the second output of electrical power is different than thefirst output of electrical power, thereby reducing a transient periodfor delivery of the electrical power to the electric motor of thepowertrain; using at least one of (1) one or more sensors onboard theaerial vehicle, and (2) data and automated observations from one or moreother aircrafts, detecting a first set of atmospheric conditions in anaircraft-operating environment that indicates contrail formation fromthe aerial vehicle would occur upon release in the environment ofexhaust water generated by one or more fuel cell stacks; and temporarilystoring the exhaust water onboard the aerial vehicle to block thecontrail formation as the aerial vehicle is navigating through theenvironment during first set of atmospheric conditions.
 8. The method ofclaim 7, further comprising: detecting a second set of atmosphericconditions in the environment in which it is unlikely to cause contrailformation from the aerial vehicle; and releasing the stored exhaustwater from the aerial vehicle into the environment as the aerial vehicleis navigating through the environment without forming a contrail.
 9. Amethod for optimizing operation of an aerial vehicle having ahydrogen-powered hybrid electric powertrain, the method comprising:providing hydrogen fuel to one or more fuel cell stacks; directing afirst amount of air to the one or more fuel cell stacks powered by thehydrogen fuel and generating a first output of electrical power for useat least by an electric motor of the hydrogen-powered hybrid electricpowertrain; operating the electric motor using the generated electricalpower, wherein the generated electrical power is provided to theelectric motor without passing through a DC-to-DC converter and/or beingstored in a battery; predicting one or more changes in an electricalpower demand of the powertrain during operation of the electric motor;controlling an amount of air flow to the one or more fuel cell stacks todirect a second amount of air to the one or more fuel cell stacks basedat least in part on the one or more predicted changes in the electricalpower demand of the powertrain, wherein the first amount of air isdifferent than the second amount of air provided to the one or more fuelcell stacks; providing the second amount of air to the one or more fuelcell stacks before occurrence of the predicted electrical power demandfor generation of a second output of electrical power by the one or morefuel cell stacks at or before occurrence of the predicted electricalpower demand of the powertrain, wherein the second output of electricalpower is different than the first output of electrical power, therebyreducing a transient period for delivery of the electrical power to theelectric motor of the powertrain; directing heat generated by the one ormore fuel cell stacks to one or more surface portions of the aerialvehicle; and using the directed heat to prevent ice formation at the oneor more surface portions of the aerial vehicle.